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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      // slice 'abcd' => 'dcba'
      // strToArr()
      strToArr("abc"); // ["a", "b", "c"];
      arrToStr(["a", "b", "c"]); // "abc"
    </script>
  </body>
</html>
